Most New Zealand farmers visiting Britain remark on the failure there to exploit the country's grassland
The reclamation of peat land has changed greatly in the last 20 years. In the past very often the enthusiastic pioneer with very little means took on the job of reclaiming peat, and his struggle and experience have given us a very valuable basis for today’s peat development.
The area of Canterbury Plains and downlands capable of cultivation is about 22 million acres. Soils
This afternoon you will be visiting Ashley Dene, the College light land farm, approximately 70 per cent of the area of which is typical of the light lands of the Canterbury Plains. The term “light” when applied to soils may have many meanings, but Canterbury farmers know only too well what they mean by the term; they think immediately of that considerable area of approximately 850,000 acres on the plains where shingle is to be found within 18 inches of the soil surface and in some cases right to the surface.
A film “Two Blades of Grass” dealing with grilssland development in southern Australia was introduced by C. M. Donald, Professor of Agriculture, The University of Adelaide, and the following discussion took place as a result of the showing of the film.
Along the coast of the North Sea from north-west France to the border of Denmark a low-lying area of 12 million acres is situated. More than 50 per cent of the land used for agriculture in this region is productive of permanent grassland. Ley farming is only of minor importance, in contrast to neighbouring countries, such as England and Denmark. In this paper some problems of grassland farming in this area will be discussed
The re are two axioms, or self-evident principles that underlie grazing standards in range management: (1) a primary objective in management is normal soil stability; and (2) Grazing standards for any particular site must be based on the inherent potential of that site. the first has an ethical, the second a scientific basis.
From the farming point of view the high country of the South Island of New Zealand is generally taken to mean all the high native grassland devoted to the growing of wool and store stock and subject to risk of Slidui. This covers some 12 million acres of country with a great variety of topography, climate, and soils, Rainfalls range from 1%. in the arid regions of Otago to over 100in. in the heavy rainfall areas close to the main ranges, and soils and vegetation vary accordingly. The winter is long and the growing season short, a maximum of 6 months in most districts.
Between the deserts and the forests are vast expanses of basins, plateaux, and grasslands with a plant cover of grasses, broadleaved herbs, shrubs, and open, arid woodlands. The semi-arid grassland, the open woods, and the desert shrubland constitute the domain of the huge western livestock industry in the 17 states lying roughly west of the 100th meridian. These are known as the range states and they are likely to remain predominantly range states because of the low precipitation, rough topography, and shallow, rocky and saline soils.
Approximately 8 million acres of the Canterbury Plains are classified as light land. The soils are a shallow, stony loam overlying an open, shingle subsoil with a very low moisture holding capacity. The rainfall ,of 25in. is fairly well distributed, but on these soils is normally inadequate for pasture growth from November to March, due to high evaporation. Under these conditions the pasture mixtures used on moister soils are unsuitable. Subterranean clover has proved the most suitable pioneer legume for this class of land and is still the basic legume for most pasture mixtures.
There are four irrigation schemes at present in Canterbury: two small ones at Redcliffe and Levels and two larger ones at Mayfield-Hinds and Ashburton- Lyndhurst. The latter two cover 48,000 and 58,000 acres. I intend to restrict my discussion of the problems of irrigating grassland in Canterbury to that part of the province covered by the Lismore silt loam with a water table seldom rising above 50ft, and with a 25 to 35in. rainfall, relatively well distributed, though with a high summer evaporation. This does not take in all the present schemes which contain some more fertile land, but it and similar soil types cover by far the greater part of both present and suggested schemes.
It was originally suggested that this paper should deal with problems associated with the management of grazings under low rainfall conditions and the title submitted was “Problems of management of grassland under low rainfall conditions in South Africa.” It was decided, however, that as much of the veld under low rainfall conditions was not grassland, it would be better to deal with the main veld regions in areas of low rainfall. The next decision to be made was what was to be considered as “low rainfall” and, after a careful study of the main veld types, it was decided that low rainfall areas would include those which enjoyed an annual rainfall of 20 inches or less.
Silage is not a replacement for good pasture management, but it is a means of making the most of a sound grassland programme. It is an effective method of preserving surpluses of immature forage for use when pasture is in short supply or completely lacking. While quality silage is an excellent feed it is still a substitute .for the original product-pasture herbage. The problem in making silage is to produce a nutritious and palatable feed and to keep the loss of nutrients at a minimum.
Although the production of good pasture is a starting point, one end point is a prime, healthy animal. lems At Weybridge, we have many animal health probassociated wrth the grazing of apparently good pastures, and it is some of these problems that I propose to discuss this afternoon: Because some of these disorders are not associated with a deficiency of minerals in the herbage itself, it may be misleading to refer to them merely as “trace element” or “mineral deficiency” diseases, which usually implies a deficient intake of some essential dietary constituent rather than a dysfunction of the mineral metabolism of the animal.
It has been estimated that there are almost l,OOO,OOO acres of light land on the Canterbury Plains. The term light land is really a misnomer in that it _ bears no relationship to the actual texture of the soil. The term is merely one which has come into general use in Canterbury to refer to land where there is a shallow depth of soil lying on top of the gravel or shingle. There is no clear definition of what constitutes light land, but it would probably be reasonable to assume that any land where the depth of soil and subsoil overlying the gravel is 16in. or less would be classed as light land.
Land development in New Zealand is essentially a matter of pasture establishment, and for the work to be economic. pastures of the perennial ryegrass-white clover type .-have generally been essential. These demand fairly exacting seed-bed and soil fertility conditions for establishment and sustained, production, and the practices that have been adopted to secure suitable conditions will form the major part of my discussion of land development
This paper deals only with the tussock grasslands of the South Island. There are areas in the North Island-on parts of the Central Plateau, and above the bush-line on the higher mountain ranges-which are clad in tussock species, but these are of relatively small extent, and have not been considered an important problem.
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